This invention pertains to a combination bumper and step for an automotive vehicle, and more particularly, to a rear bumper for a light truck or van-type vehicle.
One of the ways in which automobile and truck manufacturers are attempting to improve the average fuel efficiency of the vehicles is by reducing the weight of the vehicle components. Reduction of vehicle weight permits smaller, more fuel efficient engines to be used to power the vehicle. One area under study has been the bumpers which conventionally are made of heavy guage steel. It has been proposed that the bumpers be fabricated of aluminum or plastic material, both of which permit a weight and cost saving over the types of steel conventionally used in bumper fabrication. Bumpers made of aluminum or plastic, however, present fabrication difficulties, and also have met consumer resistance as being of questionable durability and damageability.
Rear bumpers for light trucks and van-type vehicles, in particular, present even greater fabrication difficulties than the ordinary bumper since it is desirable that a step portion be incorporated in the bumper structure to facilitate ingress and egress to the cargo area of the truck or van.
The current availability of high strength, low alloy steels having the formability characteristics of mild steels now presents the opportunity to greatly reduce the guage and thereby the weight of the metal used in a rear step bumper at only a slight cost penalty over the use of aluminum.
An investigation of the prior art has developed the following patents showing various rear step bumpers, none of which, however, disclose the specific structure of the present invention. U.S. Pat. Nos. 3,427,062 issued Feb. 11, 1969 to F. L. Struben for an "Aluminum Bumper with Horizontal Step Portion"; 3,774,952 issued Nov. 27, 1973 to E. Zorn for an "Aluminum Bumper Construction"; 3,790,200 issued Feb. 5, 1974 to C. L. Kalitta for a "Vehicle Bumper"; and 3,905,527 issued Sept. 16, 1975 to P. N. Chamberlain for a "Bumper for Camper Support Vehicles".